A typical magazine or can for linked or belted rounds of ammunition includes a plurality of partitions for subdividing the can interior into multiple compartments or bays. A continuous ammunition belt is loaded in the can with portions thereof in each bay arranged in layers built up from the bottom in serpentine fashion. From the uppermost layer in each bay, the ammunition belt is drawn over the top of the partitions and runs downwardly to the bottom of the adjacent bay. The leading end of the ammunition belt is directed out through an exit port from an adjacent bay and on to the rapid-fire gun. When the ammunition belt is withdrawn to feed successive rounds to the gun, the bays are emptied in succession. To reduce drag, the ammunition belt may be drawn over rollers positioned above the partitions, as disclosed in Trimbach U.S. Pat. No. 2,398,263.
While this loading arrangement provides optimum packaging density, problems are encountered during withdrawal of an ammunition belt, particularly when drag-reducing rollers are utilized between bays. As a bay is being emptied of its serpentine layers from top to bottom, a point is reached when the weight of the freed belt segment suspended from the roller is sufficient to pull belted ammunition rounds out of the adjacent bay, over the roller and down into the bay being emptied. These rounds "syphoned" from the adjacent bay uncontrollably pile up on the upper serpentine layer in the bay being emptied, thereby seriously impeding belt withdrawal to the point that the links between rounds can be damaged or even severed. Damage links typically result in jams, and severed links deny access to that portion of the ammunition belt beyond the break. In either case, the rapid-fire gun is shortly out of action.